SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac14e24273a0386a91718cd11dacff056155549f44565dc1fac290f748abb259' 
  AND token = 'NgPUrIFpK96sIAhM2wIxpJK5MjaOKgSCiRbTe33/7CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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