SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0d19d0893c2528d0816735b96dadada34b093507814cdb715927febfa53da9a' 
  AND token = 'vyZ0olZuScLLRr+3P3vndFi6Yb8uhp/WFcQgd0QpuDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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