SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0916cb11866c93a0de5df55d191dade1e24da82adda7a849559fc28dc16c3de' 
  AND token = 'fAi3RA4y3gYrr1Em8472IGcdvpJTU5PMbGHw4XqC2Uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}