SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a660f20b9c1a4d9ee57de6016de463f0b32e40fca89814f6867c853e96b11b47' 
  AND token = 'a7HjNRJFlCHDEjJNgO9wp/edmMt5razNMM1Kbp75hoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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